The right answer is D) homozygous for allele A and heterozygous for allele B.
The color between the two alleles A of the chromosomes are identical, while the color alleles B of the two chromosomes is different, the one that is a high appears darker and the one that is below appears clearer, so it means they are different, so they are heterozygous.
An allele is one of the different forms that can take the same gene. Alleles occupy the same position (locus) on homologous chromosomes.
The brown spotted deer would spread their genes more than the white spotted ones which would eventually lead to them completely overpowering genetically the white deer in future generations.